He's not writing a scientific paper, he's offering advice based on his experience, and I shall take that advice into consideration in my choice of gear suitable for my purposes.

I had a mirrorless and DSLR at the same time from about 2014 thru 2016 and while I did not do any scientific testing on the matter, I believe the mirrorless had significantly bigger dust issues, although none of the issues were serious enough so that the next time I turned the camera on or off, the dust was removed with the dust removal shake.

Having just returned from taking pics outside in the bright sunshine (and snow), the scenes were quite difficult to see thru the EVF. While I enjoy my mirrorless cameras, there are shortcomings in certain conditions.

Play the video from 8:50 to 10:35. Starts with: "A huge thing that that nobody talks about that much is sensor dust .....My inclination is to take seriously a reviewer who sees an actual phenomenon and describes it in depth.

Yeah dust can be a problem if you don't know what you are doing or don't take proper precautions. This is an image from my 5D in 2006 (the original) my 2nd DSLR, first day of a 2 week trip got a ton of dust from changing lenses in windy conditions by the water. The 5D wasn't a mirrorless camera, I didn't bring a rocket blower so I had to do a ton of spotting. Dust can get in any camera. I've used all sorts of Canon DSLRs and now 3 different Sonys and dust isn't any more or any less of an issue for me. I like that I can see the sensor now.

The Canon Integrated Cleaning System was introduced in 2006 - http://cpn.canon-europe.com/content/education/technical/eos_integrated_cleaning_system.doYour original 5D, introduced in 2005, predated ICS. Further, the fluorine coating to repel dust wasn't introduced until the 5DII, and there have been subsequent modifications to prevent dust sticking. You original 5D is not a good example to cite for dust on a sensor since there have been tons of improvements in the last 13 years.

Perhaps, but it is certainly appropriate when discussing how much influence the presence of a mirror has on protecting a sensor, or the inset of a sensor within the body for that matter.

Those later improvements, which made a significant difference, are not unique to SLR.

Back then I avoided 5D because it had the nickname dust magnet. This has changed completely with 40D, 5DII, etc

Dustin thanks for another one of your excellent reviews which are always informative and accessible to the reader. Like you I have owned the EOS M for some time for the same reason as you and like many on the forum I am awaiting a good FF mirrorless from Canon. As you have noted in several reviews a key feature is a really good EVF, in my case because a high percentage of my lenses are MF and I like the process of MF. I also like using tilt/shift lenses and again an EVF would seem to be a potentially very helpful tool. Your review of the a7R3 is interesting not only because of the EVF but the AF performance. I was interested to learn more of its eye AF feature performance and the improved frame rate and buffer capacity because if I buy a FF mirrorless I want it to be widely useable in different photographic scenarios. Whilst my first choice has been and remains to wait for a Canon FF mirrorless if one does not materialise soon, getting the a7R3 when there is a good $ deal on offer will be an option.

Can I ask for more explanation as to how the zoom feature works in the EVF? Such as:1) How do you activate the zoom/what controls do you use?2) What settings are there to control the zoom feature (e.g. zoom extent)?3) After you take a shot, what happens next time? Does the EVF retain the zoom or must it be reactivated again using the same sequence?4) What point/region does the EVF zoom about?5) Can you move the zoom region by touch dragging on the viewfinder?6) Is there any "auto zoom" type feature like the EOS M5 has with native EFM lenses. For example can you set the body up to zoom automatically when you half press the shutter button?

I appreciate any info that you can provide on this. Thanks again. Phil

Thanks for such a thorough and well-written review. I'm curious: what do you find as the autofocus speed difference between adapted and native lens on A7R3 using the MC-11?

Thanks!

The a7R3's focus system provides a much better experience than I've previously seen with the MC-11, but ultimately quality of focus is still lens-specific. Newer lenses tend to do better. The new Tamron SP primes focus great. The Canon 35L II is very good, and the 100-400L II is okay, the Canon 100L is meh.

Dustin thanks for another one of your excellent reviews which are always informative and accessible to the reader. Like you I have owned the EOS M for some time for the same reason as you and like many on the forum I am awaiting a good FF mirrorless from Canon. As you have noted in several reviews a key feature is a really good EVF, in my case because a high percentage of my lenses are MF and I like the process of MF. I also like using tilt/shift lenses and again an EVF would seem to be a potentially very helpful tool. Your review of the a7R3 is interesting not only because of the EVF but the AF performance. I was interested to learn more of its eye AF feature performance and the improved frame rate and buffer capacity because if I buy a FF mirrorless I want it to be widely useable in different photographic scenarios. Whilst my first choice has been and remains to wait for a Canon FF mirrorless if one does not materialise soon, getting the a7R3 when there is a good $ deal on offer will be an option.

Can I ask for more explanation as to how the zoom feature works in the EVF? Such as:1) How do you activate the zoom/what controls do you use?2) What settings are there to control the zoom feature (e.g. zoom extent)?3) After you take a shot, what happens next time? Does the EVF retain the zoom or must it be reactivated again using the same sequence?4) What point/region does the EVF zoom about?5) Can you move the zoom region by touch dragging on the viewfinder?6) Is there any "auto zoom" type feature like the EOS M5 has with native EFM lenses. For example can you set the body up to zoom automatically when you half press the shutter button?

I appreciate any info that you can provide on this. Thanks again. Phil

The nice thing about Sony is that you map most features (including focus zoom) to a number of buttons. I personally have it mapped to the AEL button. You do have choices about magnification level and what area of the image is magnified, and even choices on whether you want a color overlay added (I mostly don't use Focus Peaking as I feel it makes the shooting process less organic). Native mount manual focus lenses (with electronics) will trigger an automatic zoom when you move the MF ring, but not third party lenses. It's about as good as it gets right now for MF, particularly when you consider you also get true image stabilization on those lenses to boot.

Dustin thanks for another one of your excellent reviews which are always informative and accessible to the reader. Like you I have owned the EOS M for some time for the same reason as you and like many on the forum I am awaiting a good FF mirrorless from Canon. As you have noted in several reviews a key feature is a really good EVF, in my case because a high percentage of my lenses are MF and I like the process of MF. I also like using tilt/shift lenses and again an EVF would seem to be a potentially very helpful tool. Your review of the a7R3 is interesting not only because of the EVF but the AF performance. I was interested to learn more of its eye AF feature performance and the improved frame rate and buffer capacity because if I buy a FF mirrorless I want it to be widely useable in different photographic scenarios. Whilst my first choice has been and remains to wait for a Canon FF mirrorless if one does not materialise soon, getting the a7R3 when there is a good $ deal on offer will be an option.

Can I ask for more explanation as to how the zoom feature works in the EVF? Such as:1) How do you activate the zoom/what controls do you use?2) What settings are there to control the zoom feature (e.g. zoom extent)?3) After you take a shot, what happens next time? Does the EVF retain the zoom or must it be reactivated again using the same sequence?4) What point/region does the EVF zoom about?5) Can you move the zoom region by touch dragging on the viewfinder?6) Is there any "auto zoom" type feature like the EOS M5 has with native EFM lenses. For example can you set the body up to zoom automatically when you half press the shutter button?

I appreciate any info that you can provide on this. Thanks again. Phil

The nice thing about Sony is that you map most features (including focus zoom) to a number of buttons. I personally have it mapped to the AEL button. You do have choices about magnification level and what area of the image is magnified, and even choices on whether you want a color overlay added (I mostly don't use Focus Peaking as I feel it makes the shooting process less organic). Native mount manual focus lenses (with electronics) will trigger an automatic zoom when you move the MF ring, but not third party lenses. It's about as good as it gets right now for MF, particularly when you consider you also get true image stabilization on those lenses to boot.

Regarding (2): I’ve only used it with manual triggering, during which progressively zooms in 3 times. I don’t believe you have any control over it. Once you have reached the largest magnification, the next tap returns to the full image.

Regarding (3): magnify disables after you take a photo

Regarding (4): in MF, it defaults to the center, but you can move around with the thumbstick. In DMF, I believe it magnifies in the area of the last AF acquisition, but I could be mistaken.

Interested that you disable the touch screen. I noted Dustin's comments on the screen in his review. Why do you disable your screen?

If I shot with the rear display things may be different, but mainly, the location of the screen doesn’t work with my hand placement. Also I shoot with my left eye, so there isn’t a clean place to shoehorn in my finger.

Additionally, I don’t like the lack of sensory feedback. I’m not against touch panels for camera controls, but so far it doesn’t work well for me.

A7rii doesn’t have a touch screen, so yes that would be frustrating...

I must be misremembering with another Sony body I had borrowed. I just recall that the touchscreen experience was awful :X

It was many months ago, last year, so apologies for mixing it up. I suspect it must have been the a6500, as this is the only other Sony camera I've spent a significant amount of time with (outside of a camera shop).